I still don't like this, but I don't think it's as bad as I originally did.

I think 1976 was the first model year to have any sort of government-mandated emissions controls. If the law were set up to only require that cars from model year 1976 or later have to meet the emissions standards from when they were originally sold, that would be no problem. But if they are required to meet emissions standards which they were not even designed to meet from the factory, that's asking a bit much.

Of course the article above doesn't really get into much actual detail of the regulation, so who knows what the hell it actually says.